The present review focuses on the relation to human behavior and development of anthropometric or dietary indexes of mild-to-moderate malnutrition. The primary goal of the review is to integrate previous research findings with current findings from correlational studies conducted over the past decade. From this integration, the following conclusions may be drawn: 1) Chronic, mild postnatal malnutrition is associated with a variety of cognitive and behavioral deficits across the life span. The role of prenatal malnutrition in this process is less clear. 2) To understand the role chronic mild malnutrition plays in behavior and development, it is necessary to move beyond protein-calorie deficits to consider the role of intake of animal source foods and specific micronutrients such as iron, zinc and B vitamins. 3) Chronic mild malnutrition is embedded in a host of other biological and psychosocial risk factors. As a result, chronic mild malnutrition appears to be a necessary but insufficient condition for producing behavioral deficits. 4) The salience of chronic mild malnutrition as a risk factor is accentuated when other psychosocial-contextual risk factors are also present or when multiple low-level nutrient deficits are interacting. Suggestions for future research directions include an emphasis on interactions between nutrients and between specific psychosocial and nutritional risk factors; the ways in which individual (e.g., gender) or cultural characteristics can moderate nutrition development relations; and a broader range of populations, such as sibling or elderly caregivers, and outcome variables, such as social-emotional development, temperament and mental health.